The cellular and molecular biology of the mycoplasmas will be investigated. First, electron microscopic studies of Mycoplasma pulmonis will examine whether these cells have a specialized terminal structure, similar to the two other mycoplasmas that exhibit gliding motility and are inhibited by cytochalasin B. Second, studies will continue to try to visualize the M. gallisepticum cytoskeletal elements in vivo. Third, isolation and characterization of the mycoplasma folded chromosome will continue, to try to utilize this system for an understanding of DNA structure and packaging.